.. index:: Chebyshev
This function calculates a partial Chebyshev expansion
\sum_{n=0}^N a_n T_n(a+bx)
where a_n are the expansion coefficients and T_n(x) are Chebyshev polynomials of the first kind defined by the reccurence relation
T_0(x)=1 \,\!
T_1(x)=x \,\!
T_{n+1}(x)= 2xT_n(x)-T_{n-1}(x) \,\!
Coefficients a and b are defined to map the fitting interval into [-1,1] interval.
Chebyshev function has tree attributes (non-fitting parameters). First is 'n' which has integer type and sets the expansion order and creates n+1 expansion coefficients (fitting parameters). The parameter names have the form 'Ai' where 'A' is letter 'A' and 'i' is the parameter's index starting from 0.
The other two attributes are doubles 'StartX' and 'EndX' which define the expansion (fitting) interval.
.. attributes::
.. properties::
.. categories::
.. sourcelink::